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This study utilizes numerical simulations and dimensional analysis to investigate the impact of the two-phase outlet on flow field characteristics and separation efficiency of the separator. The study revealed a boundary layer separation at the water outlet, which was subsequently addressed to reduce energy losses in the separator. Dimensional analysis considered the influences of operational, structural, and physical parameters on the separator's performance. With other structural parameters held constant, separation efficiency is directly proportional to the ratio of inlet and oil-outlet diameter. Additionally, the separation efficiency is also associated with Re and the ratio of the inlet to the water-outlet diameter. When the diameter of the water outlet is constant, the axial vortex separator achieves optimal separation when the ratio of inlet and water-outlet diameter is 0.563, with a maximum separation efficiency of 97.00%. The optimal separation efficiency is reached at Re=22,908 under various operational conditions. Separation efficiency increases with water content, peaking at an inlet water content of 0.9 across different structural parameters. Separation efficiency shows an increase followed by a decrease with the rise in inlet flow rate(vi), achieving the best performance at vi=3m/s for the different separator structures studied. [ABSTRACT FROM AUTHOR]

With the continuous expansion of water drive oil fields and the increasing difficulty of oil recovery, the accuracy requirements for predicting water drive performance are also increasing. Based on this, this article utilizes system modeling algorithms to construct a high-precision water drive dynamic prediction platform, and conducts model validation and application research on actual oil production data, achieving certain successful results. This platform has built a complete, efficient, and operable water drive dynamic prediction method, which can accurately and stably predict the oil, water, and gas production of water drive oil recovery, achieving the goal of real-time monitoring of oil production wells. In practical applications, the platform effectively solves the problem of predicting water drive production capacity in oil production wells by combining data regression analysis and grey theory. Therefore, the research on the system modeling algorithm based water drive dynamic prediction platform and its application will provide valuable and practical references for the production management and sustainable development and management of resource oceans in the oilfield field. [ABSTRACT FROM AUTHOR]

In this study, the recent advances in standalone membrane technologies were investigated for produced water treatment and reclamation. The effect of operating parameters (i.e. temperature, flow rate, velocity, and pH) on membrane fouling were studied in detail. Results showed that microfiltration suffered severe fouling from suspended particles and flux deterioration reacheed 90 % in less than 1 h. Ultrafiltration showed enhanced removal of oil up to 95 % however, membrane hydrophilicity needs to be increased and the suspended particulates should be minimized to sustain operation. Nanofiltration was more prone to fouling with maximum oil removal 99 % and removal of 10 % to 20 % of dissolved solids. Reverse osmosis (RO) performance decreased rapidly against mild salts and oil concentrations in the range of 2000 ppm salts and 150 ppm crude oil and was therefore not suitable for standalone. Developed technologies such as membrane distillation (MD) and forward osmosis (FO) showed remarkable operation stability against high concentrations of oil and salts (1000 ppm crude oil and up to 150,000 ppm of salts). Hybridization of nanofiltration or RO with MD or FO processes showed promising results in pilot tests. [ABSTRACT FROM AUTHOR]

Oil production in most of the old reservoirs is expected to decline, and this will create a gap between the supply and demand of oil in the world. Meanwhile, there are still huge volumes of hydrocarbons in unconventional reservoirs. Intensive technological approaches are needed to ensure adequate oil is recovered than developing other new fields that are more expensive economically. Therefore, there is a rising interest in developing effective improved oil recovery techniques to increase oil recovery from the depleted oil fields or unconventional oil resources. This study mainly intends to compare between the water alternating gas (WAG) and the water huff-n-puff techniques for oil recovery in a tight oil reservoir, based on their effectiveness, their recoveries, economical factors, as well as assessing the factors that affect the recovery based on both of the techniques. The modelling and designing of the reservoir for the Jilin tight oil field and its simulation were performed by the ECLIPSE 300 software. The result showed that, after the simulation of 2922 days, WAG has better results than using a water huff-and-puff technique by providing a total of 30,453.271 Sm3 of the total field oil and the water huff-and-puff method has a total field oil production of 1,726.389 Sm3. Besides good oil recovery, the WAG method has shown higher water production compared with that of the water huff-and-puff method, with 46157.715 Sm3, whereas the water huff-and-puff method has only produced a total field water of 138.874 Sm3 for the whole 2922 days of simulation. Furthermore, the WAG best mode that shows an optimum oil recovery efficiency of 47.40% is an injection mode by starting with water injection followed by gas injection (CO 2) for 1-year cycle each. Thus, WAG is a preferential candidate for the development of tight oil reservoirs. [ABSTRACT FROM AUTHOR]

The petroleum industry generates a massive amount of oily water discharge from oil–water separators. Oily water will cause a major environmental risk if not treated before discharge. The challenge is to propose a suitable low maintenance cheap treatment method. This study represents a second phase of testing polyester fibers as deep bed filtration media to treat the produced oily water. The previous, first phase, study investigated the efficiency of the polyester fiber by conducting short duration filtration tests using 40 cm polyester fiber filters. From the first phase study, two suggestions can be deduced to optimize the oil removal efficiency of polyester fiber filters in long duration field processes and to use either large number of short filters with low flow capacity or less number of long filters with high flow capacity. The two methods were employed and tested separately in this study. The results of both methods clearly showed the ability of the polyester fiber deep bed filters to produce high-quality brine of less than 5 ppm oil concentration. The polyester fibers filter was proven to be a competitor with the existing materials used in the industry. [ABSTRACT FROM AUTHOR]

Produced water, a major by-product of oil and gas production, represents the most significant amount of waste by volume in the oil and gas industry. Focusing on the hydrocarbon's lifecycle, this review delves into the composition and global variations of produced water. It assesses the current treatment methods for their effectiveness and their potential for reuse in sectors beyond oil and gas, such as agriculture. The review highlights the environmental trade-offs in maximising energy production, analysing the ecological implications of produced water disposal in marine environments and the potential risks to marine biodiversity. Regional regulatory frameworks and their role in mitigating these environmental impacts are examined, alongside the challenges faced in standardising treatment solutions due to the complex nature of produced water. The conclusion underscores the need for continuous research to develop innovative and effective treatment technologies and advocates for a balanced approach to energy production that prioritises environmental stewardship. [Display omitted] • Untreated produced water has detrimental effects in the marine environment. • Produced water quality is variable depending on location and hydrocarbons exploration techniques. • Produced water management is based on its characteristics and regional regulations. • Produced water quantity increases with time of field exploration. • Produced water is treated for environmental discharge or for reuse within or outside the oil and gas industry. [ABSTRACT FROM AUTHOR]

Overfishing, bycatch, and habitat loss and alteration during the late 19th century to the end of the 20th century caused significant declines in Atlantic Sturgeon Acipenser oxyrinchus stock abundances along the Atlantic coast. To prevent further stock reductions, a coastwide harvest moratorium was implemented in 1998. With fishery‐dependent data unavailable to inform stock management, fishery‐independent surveys contribute vital information for monitoring population trends by providing data for evaluating the effectiveness of the moratorium and for informing recovery planning. In 2004, a standardized monitoring survey was developed to assess trends in the relative abundance of juvenile Atlantic Sturgeon in the Hudson River, New York. The multimesh anchored gill‐net survey randomly sampled locations in soft, deep depositional areas of Haverstraw Bay from late February through early May. Predicted length‐at‐age relationships were used to infer annual age structure and to examine the relationships between age and annual catch rates. Generalized additive regression modeling was used to describe the relationships between the environmental variables and catch rates and to standardize the abundance index to account for variability in environmental conditions over time. Atlantic Sturgeon catch rates generally increased with increasing water temperature and salinity, and the standardized abundance index (accounting for environmental variability) was highly correlated with the nominal abundance index. In the 16 years of annual monitoring, there has been a significant increase in the relative abundance of juvenile Atlantic Sturgeon. The average catch rate in recent years (2012–2019) is more than twice that observed during the first 8 years (2004–2011) of the survey, as the effects of the moratorium are expected to be delayed due to the long maturation period of Atlantic Sturgeon. These trends suggest that juvenile Atlantic Sturgeon in the Hudson River may be recovering in response to the moratorium and demonstrate the need for long‐term fisheries‐independent monitoring to document abundance trends in slow‐maturing, long‐lived species. [ABSTRACT FROM AUTHOR]

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Uniform CO2 corrosion of carbon steel facilities is often a major problem when handling produced water in the oil and gas fields. High amounts of dissolved salts are often present in produced water. A limited number of research studies has been conducted on the effect of salt concentration on uniform CO2 corrosion. In this study, the effect of NaCl concentration on uniform CO2 corrosion of X65 carbon steel was investigated in CO2 saturated aqueous solutions using a rotating cylinder system at 30 °C, autogenous pH, and 1 bar total pressure in an NaCl concentration range of 0?4.27 molality (m) (0?20 wt.%). With increasing NaCl concentration, the corrosion rate increased sharply and reached its maximum value at ~0.17 m (1 wt.%) NaCl and then decreased with further increase in NaCl concentration. The observed trend in the corrosion rate with increasing NaCl concentration was primarily a consequence of the change in the cathodic limiting current density, which was the main factor controlling the rate of the overall corrosion process. The additional factor was the change in the rate of the anodic reaction with salt concentration. [ABSTRACT FROM AUTHOR]

Oilfield produced water, a toxic and saline byproduct of the oil and gas industry, has become a global concern due to its adverse environmental and human health impacts. With large volumes of oilfiled produced water generated annually and predictions of even higher volumes in the near future, effective treatment and resource recovery are imperative. This review paper explores the potential of membrane technology, particularly integrated membrane systems, in treating and recovering valuable elements from oilfield produced water. The increasing attention to this topic is evident, but research on resource recovery still needs to be expanded. Membrane technology offers a promising solution due to its efficiency and minimal need for chemical additives or thermal inputs. However, challenges such as fouling, resistance to oil and organics, and economic viability must be addressed. By discussing oilfield produced water characteristics, treatment methods, practical applications, challenges, and prospects, this review underscores the transformative role of membrane technology in turning oilfield produced water into a valuable resource. Additionally, it emphasizes the importance of research in developing anti-fouling membranes, sustainable waste management techniques, and efficient cleaning protocols while considering economic implications and market dynamics for resource recovery. [Display omitted] • Oilfield produced water can be transformed from waste to a valuable resource. • Reusing produced water is economically and environmentally beneficial. • Membrane can treat produced water with high-quality permeate. • Integrated membrane systems offer optimal outcomes in produced water treatment. [ABSTRACT FROM AUTHOR]

For offshore oil and gas production facilities, overboard disposal of treated produced water (PW) remains a principal waste management option, and regulatory frameworks have been established to manage these discharges. Risk-based assessment (RBA) of PW, which aims to quantify potential impacts on the environment, has been adopted in some regulatory systems, but is also applied by oil and gas operators as part of their risk management systems. In 2020, the International Association of Oil and Gas Producers published a guidance document, including a four-tiered assessment framework aiming for a broader understanding and consistent application of PW RBA globally. The current study reviewed case studies and categorised them along the proposed assessment tiers. Regulatory developments are shown to be key drivers for the application of PW RBA globally, but required tools are often to resource intense for early risk screening. The proposed framework promotes the use of existing data, read-across techniques, and non-animal testing in two initial screening tiers, characterised by little to no sampling. In addition, it allows to refine higher tier assessments through the application of species sensitivity distributions and the inclusion of exposure time to avoid conservative assessment factors. This enables assessments to better approximate observations from field verification, included as a final tier to determine the level of discernible effects. The proposed tiered assessment approach can be considered a novel way to scale assessment efforts to the situation especially in cases where resources are limited, priorities for further investigations need to be set, rapid evaluation of hazard levels is required, sampling logistics and transport of large volumes is complicated and/or there is an opportunity for reduced animal testing. This makes early assessments more effective and ensures logical and efficient actions are triggered for understanding and managing environmental risks of produced water discharges. • Risk-based methods quantify potential environmental impact from offshore discharges. • The proposed framework guides scaling of efforts in assessing and managing risks. • Regulatory developments are key drivers for the application of risk-based methods. • Screening tools enable rapid evaluation of hazard with reduced animal testing. • Advanced models close gaps between risk assessments and field verification results. [ABSTRACT FROM AUTHOR]

Membrane hydrodynamic irreversible oil fouling is a pressing issue. Here, an antifouling Al 2 O 3 @TiO 2 membrane with excellent wettability was created using the sol-gel method to create an anatase nano-TiO 2 coating on the surface of an Al 2 O 3 ceramic membrane. Analyzing the separation performance of an Al 2 O 3 @TiO 2 membrane on simulated oily emulsions determined the amount of TiO 2 covered on the membrane surface (0.8 mol·L−1). Under the synergy of hydrophilic nano-TiO 2 and ultraviolet (UV) light, the Al 2 O 3 @TiO 2 membrane demonstrated improved wettability and self-cleaning ability and maintained favorable separation performance (769.23 L·m−2·h−1, 97.75%, 1.23 mg·L−1) after 6 h of continuous separation of the actual oilfield produced water. After 30 min of UV illumination, the membrane flux recovered completely. This is due to the fact that the active substances (eg.,·OH,·O 2, and 1O 2) generated in situ on TiO 2 on the membrane surface after UV illumination weakened the interaction of membrane surface fouling, resulting in less oil fouling. In addition, the Al 2 O 3 @TiO 2 membrane maintained extremely outstanding oil resistance stability and recoverability during high-intensity hydraulic flushing and 25 cycles of testing. This study provides a theoretical basis for the engineering application of ceramic membranes in oilfield-produced water treatment. [Display omitted] ● The membrane showed super hydrophilic and anti-fouling properties. ● The membrane had photoinduced self-cleaning performance. ● The membrane could continuously treat actual oilfield produced water with high performance. ● This study provided a theoretical basis for the engineering application of ceramic membranes in actual oil fields. [ABSTRACT FROM AUTHOR]

Produced water (PW) is the subsurface water brought to the surface during oil and gas production. PW is primarily disposed of by deep well injection, but it can be treated for beneficial use applications. However, efficient technologies for treating hypersaline PW with complex water chemistry are limited. This study developed an innovative, multifunctional photocatalytic membrane distillation (PMD) technology using hydrophobically modified tubular ceramic membranes coated with TiO 2 nanoparticles as photocatalysts for treating unconventional PW. The effects of membrane modifications were characterized in terms of membrane morphology, pore size, chemical functionality, zeta potential, hydrophobicity, liquid entry pressure, water production, permeate water quality, and membrane fouling and scaling propensity. The desalination performance of the PMD technology was demonstrated using unconventional PW with total dissolved solids concentrations of 135,000 mg/L and 175,000 mg/L, and NH 3 -N concentrations of 1551 mg/L and 613 mg/L, respectively. The novel PMD concept provides a promising technology for hypersaline PW treatment, and TiO 2 coating significantly reduced membrane fouling and scaling, improved distillate quality, and maintained stable permeate flux. The photocatalyst activation by ultraviolet-light emitting diodes (UV-LED) light further increased the permeate flux and enhanced the total organic carbon removal from 82.0% (without UV-LED) to 89.7% (with UV-LED). UV-LED irradiation did not affect ammonia and metals removal in PMD, reaching 99.4% and > 99.99% removal, respectively. [Display omitted] • Photocatalytic membrane distillation (PMD) was developed using TiO 2 -coated ceramic membrane. • PMD effectively treated hypersaline produced water (PW) with salinity 13.5% and 17.5%. • PMD achieved high removal of > 99.99% metals and 89.7% organics from PW. • PMD significantly reduced fouling and maintained a stable operation of PW treatment. • Ammonia in PW permeated to membrane distillate and requires further treatment. [ABSTRACT FROM AUTHOR]

The oil and gas (O&G) industry has expanded significantly and brought to the surface large volumes of saline water called produced water (PW), which comprises of underground formation water, injection water, and chemical additives used during extraction and production. PW is traditionally managed via injection wells, evaporation/seepage pits, or recycling for on-site operations. There is increasing interest in PW treatment and reuse outside O&G fields due to freshwater scarcity and concerns about seismic events linked to deep-well injection. Adopting treated PW for reuse outside the O&G sector needs to address the challenges of complex water chemistry, limited toxicity data, and knowledge gaps for appropriate regulatory responses, including risk assessment frameworks on human health and the environment, socio-technical–economic assessments of treatment and reuse applications, and long-term demonstrations and monitoring of fit-for-purpose reuse. This opinion paper proposes a holistic, state-of-the-science pathway for PW treatment, management, and fit-for-purpose reuse outside O&G fields. • Current applications of PW treatment and reuse in the United States are studied. • Opportunities for broad PW reuse inside and outside O&G fields are emphasized. • Regulatory framework and risk assessment approaches for PW reuse are reviewed. • Challenges impeding PW reuse outside O&G fields are discussed. • Human health and environmental risk assessment framework is proposed. [ABSTRACT FROM AUTHOR]

Nonionic polyether water clarifier is commonly used in the treatment of produced water from offshore oilfield. At the meantime, hydrophobically modified polyacrylamide (HMPAM) is one of the commonly used polymer oil displacement agents. Predicting the influence of HMPAM on the performance of nonionic polyether water clarifier is of great significance for the treatment of produced water. This work explored the influence of different HMPAMs on the hydrophilic-lipophilic deviation (HLD) equation of a typical nonionic polyether water clarifier AE411 based on the HLD theory, and predicted their influences on the performance of AE411. The results showed that HMPAM had no effect on the parameter K (reflecting the interaction between AE411 hydrophilic groups and oil phase) and c t (reflecting the temperature sensitivity of AE411) in HLD equation of AE411, but reduced the parameter C cn (reflecting the micelle structure of AE411 in water) and led to an increase in temperature corresponding to AE411′s HLD = 0. It was predicted that higher temperature was needed to ensure the performance of AE411. The experimental results of produced water treatment confirmed this prediction. The results of the paper validated the reliability of HLD application in the field of produced water treatment and provided some guidance for the development of nonionic polyether water clarifier. [Display omitted] • HMPAM had no effect on the parameter K of HLD equation of AE411. • HMPAM reduced the parameter Ccn of HLD equation of AE411. • HMPAM leaded to an increase in temperature corresponding to AE411′s HLD = 0. [ABSTRACT FROM AUTHOR]

In the present study, we compared the toxicity and associated chemical characterizations of flowback and produced water (FPW) collected from a single horizontal hydraulically fractured well at different time points during FPW production. Since few studies on whole mixture toxicity related to FPW exist, our aims were to determine both overall toxicity of the FPW mixture in a suite of organisms (Daphnia magna, Lumbriculus variegatus , Danio rerio, and Oncorhynchus mykiss) and also determine if toxicity changes depending on variation in FPW chemical properties as a function of time sampled (1.33, 72, and 228 h FPW samples collected immediately post-well production onset were analyzed in current study). FPW chemical composition was determined via quadra-pole inductively coupled plasma – mass spectrometry/mass spectrometry (ICP-MS/MS), full-scan high performance liquid chromatography/Orbitrap mass spectrometry (HPLC/Orbitrap-MS), and gas chromatography-mass spectrometry (GC-MS). We observed that FPW sampled later in the production process contained higher ion and total dissolved solids concentrations, whereas the highest concentrations of dissolved organic compounds were observed in the earliest FPW sample analyzed. Toxicity associated with FPW exposure was deemed to be species-specific to a certain extent, but general trends revealed the earliest FPW sampled contained highest toxic potential. Accordingly, we theorize that although the saline conditions of FPW are the foremost toxicological drivers to freshwater organisms, dissolved organics associated with FPW significantly contribute to the overall toxicity of exposed organisms. Image 1 • Temporal sampling of Hydraulic Fracturing Flowback and Produced Water (FPW) toxicity. • Earliest FPW samples had highest toxicity amongst most aquatic species examined. • Increases in FPW total dissolved solids occurs as FPW sampling continues. • Organics are highly variable but are generally highest in earlier FPW samples. • Species specific sensitivity to FPW reflects differences in organism biology. [ABSTRACT FROM AUTHOR]

• The paper examines hydraulic fracturing water demands in semi-arid Colorado. • It asks how the energy industry secures water despite social and material barriers. • It shows how "subsurface irrigation" differs from surface irrigation. • It details how regulators have adapted to hydraulic fracturing's idiosyncrasies. • Assemblage theory offers a means for examining/questioning energy-water relations. This paper explores how a novel and water-intensive method of energy production – high-volume hydraulic fracturing (a.k.a., "fracking" or "fracing") – has taken hold in a river basin that is over-appropriated, is managed via a water governance regime that did not anticipate hydraulic fracturing's idiosyncrasies, and where public concern about dedicating freshwater to hydrocarbon production is high. Via a grounded examination of hydraulic fracturing water use in Colorado's busiest oilfield and most crowded river basin, I argue that the practice has come to exist – and persist – despite these countervailing forces because it is an ephemeral energy-water assemblage. It is always in motion, is tough to monitor, and emerges only to disappear and reemerge again. This shape-shifting capacity distinguishes hydraulic fracturing from better-known energy-water couplings such as the hydroelectric dam and from historical surface irrigation practices in the American West. It also has consequences. While the uncritical energy-water literature suggests that these energy-water relations have been sufficiently characterized by volumetric gallons-per-well estimates, and the physical ephemerality of the hydraulic fracturing assemblage keeps its on-the-ground complexities elusive, an abridged and uncomplicated picture of hydraulic fracturing endures in the academic literature and public discourse. The partial understandings that result make this assemblage simpler to produce and reproduce. This study responds to calls for more nuanced analyses of energy-water relations. It also contributes to assemblage theory by examining the relationship between instability and stability in the lives of an assemblage, which underscores the importance of processes of disassembly and reassembly within assemblage-style analyses. [ABSTRACT FROM AUTHOR]

• Feasibility study of calcium bentonite ceramic hollow fiber membrane for oily produced water separation. • Pre-treatment effect of calcium bentonite on the physicochemical properties was evaluated. • The CaB-HFM 45 sintered at 1100 °C possessed the optimal characteristics including an adequate sponge-like and void-like pore structure, a mechanical strength of 95.33 ± 2.6 MPa, an average pore size of 1.015 µm, and a porosity of 51.04%. • The optimized fabricated CaB-HFM 45 resulted in excellent water permeation (505.7 ± 29.5 L/m2.h.bar) and oil rejection performance of up to 97%. • The fabricated CaB-HFM 45 could serve as an alternative ceramic hollow fiber membrane for the treatment of oily produced water. Ceramic hollow fiber membranes (CHFMs) have been recognized as an effective method in treating oily produced water (OPW). However, the high cost of CHFMs deters industries for implementing them on a large scale. This research investigates the feasibility of using calcium bentonite as CHFMs for treating OPW and examines the effect of sintering temperatures on the physical properties, mechanical properties and performance of calcium bentonite hollow fiber membranes (CaB-HFMs). The calcium bentonite undergoes several pre-treatment processes and is subsequently characterized. The fabricated CaB-HFM with 45 wt% of calcium bentonite content (CaB-HFM 45) is characterized and examined for water permeation and OPW rejection performance in a cross-flow filtration mode for 3 h. Among the CaB-HFM 45, the membrane sintered at 1100 °C displayed optimum characteristics for OPW treatment, including a good morphology with adequate sponge-like and void-like pore structure, a mechanical strength of 95.33 ± 2.6 MPa, an average pore size of 1.015 µm and a porosity of 51.04%. Surprisingly, the membrane also displayed strong hydrophilic behavior (26.05°) and strong underwater oleophobic behavior (141.20°), resulting in outstanding water permeation performance (505.7 ± 29.5 L/m2.h.bar) and oil rejection performance of up to 97%. These remarkable features highlight the membrane's potential as a promising solution for OPW treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is a major process for oil and natural gas production in the United States, and sand mines in Western Wisconsin provide highly desirable sand for the fracturing industry. After being mined, sand is wet-sieved to isolate economical-size fractions. Polyacrylamide is used as a flocculant to settle out the fine particles, resulting in a silt and clay-rich byproduct referred to as waste fines. This waste fines material can be used as a soil amendment to augment the water-holding capacity of naturally sandy soils. Residual polyacrylamide degrades quickly in the environment, but the fate of the nitrogen in the polymer is largely unknown. To characterize the behavior of nitrogen in this waste fines substance, a column study was conducted. Columns were packed with waste fines and leached with 0, 1, and 10 mg L–1 NO3–N solutions. Results show significant leaching loss of NO3–N at 1 pore volume in each treatment with peak concentrations averaging 60 mg L–1, indicating the material is a source of NO3–N. After the peak at 1 PV the 1 and 10 mg L–1 columns had NO3–N concentrations lower than the input solutions, suggesting adsorption by the waste fines. Collectively, these results indicate the waste fines could be both a source and sink of NO3–N. More research is needed to understand the mechanisms of NO3–N behavior in this material. [ABSTRACT FROM AUTHOR]

Shale gas has been denoted as one of alternative energy sources for meeting future energy demands and received global attention, especially with aid of technological advances in horizontal drilling and hydraulic fracturing. This study focuses specially on synergistic optimization of the Marcellus shale-gas-water supply chains with consideration of economics and pollutants mitigation through a mixed-integer bi-level programming model. This model could account for conflicting objectives and interactions between different stakeholders. Operational decisions regarding well drilling schedule, production planning, freshwater withdrawals, wastewater disposal, and infrastructure expansion would be provided for both leader and follower in a sequential manner. Moreover, comparative analyses among the bi-level model and the two single-level models disclose that the bi-level decisions would increase nearly 8.6% of shale gas production, 12.3% of economic benefits, 8.0% of water consumption, and 4.5% of pollutants discharge as compared with the environmentally-aggressive policies. By contrary, the bi-level decisions would lead to 8.5% decrease of shale gas production, 6.1% decrease of economic benefits, 7.3% decrease of water usage, and 6.0% decrease of pollutants discharge when compared with the economically-aggressive solutions. These findings could assist the stakeholders in resolving of conflicts among pollutants reduction, economic performance, and water supply security. [ABSTRACT FROM AUTHOR]

Formation water is produced during the whole lifetime of a hydrocarbon reservoir alongside the oil and/or gas and it represents the main part of the produced fluid. The produced formation water is separated during the process of dehydration. This paper deals with the formation water separation costs regarding the fields A, B and C which are located in the western part of the Sava Depression. The dehydration process regarding field A is executed in three locations, and in fields B and C. it is executed in one location. The technological system of formation water separation and the geological characteristics of the above-mentioned reservoirs is represented. A statistical analysis regarding the formation water separation costs has been made. The costs have been statistically estimated and a correlation between the costs relevant for the usual formation water separation process has also been made. The purpose of the analysis of the cost of the dehydration process is the optimization of the production system and cost control of the process. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing to extract oil and natural gas reserves is an increasing practice in many international energy sectors. Hydraulic fracturing flowback and produced water (FPW) is a hyper saline wastewater returned to the surface from a fractured well containing chemical species present in the initial fracturing fluid, geogenic contaminants, and potentially newly synthesized chemicals formed in the fracturing well environment. However, information on FPW toxicological mechanisms of action remain largely unknown. Both cardiotoxic and respirometric responses were explored in zebrafish ( Danio rerio ) embryos after either an acute sediment-free (FPW-SF) or raw/sediment containing (FPW-S) fraction exposure of 24 and 48 h at 2.5% and 5% dilutions. A 48 h exposure to either FPW fraction in 24–72 h post fertilization zebrafish embryos significantly increased occurrences of pericardial edema, yolk-sac edema, and tail/spine curvature. In contrast, larval heart rates significantly decreased after FPW fraction exposures. FPW-S, but not FPW-SF, at 2.5% doses significantly reduced embryonic respiration/metabolic rates (MO 2 ), while for 5% FPW, both fractions reduced MO 2 . Expression of select cardiac genes were also significantly altered in each FPW exposure group, implicating a cardiovascular system compromise as the potential cause for reduced embryonic MO 2 . Collectively, these results support our hypothesis that organics are major contributors to cardiac and respiratory responses to FPW exposure in zebrafish embryos. Our study is the first to investigate cardiac and respiratory sub-lethal effects of FPW exposure, demonstrating that FPW effects extend beyond initial osmotic stressors and verifies the use of respirometry as a potential marker for FPW exposure. [ABSTRACT FROM AUTHOR]

We present a novel approach to environmental risk assessment of produced water discharges based on explicit impact and probability, using a combination of transport, fate and toxicokinetic-toxicodynamic models within a super-individual framework, with a probabilistic element obtained from ensemble simulations. Our approach is motivated by a need for location and species specific tools which also accounts for the dynamic nature of exposure and uptake of produced water components in the sea. Our approach is based on the well-established fate model DREAM, and accounts for time-variable exposure, considers body burden and effects for specific species and stressors, and assesses the probability of impact. Using a produced water discharge in the Barents Sea, with early life stages of spawning haddock, we demonstrate that it is possible to conduct a model-based risk assessment that highlights the effect of natural variations in environmental conditions. The benefits, limitations and potential for further improvements are discussed. • We describe a model for impact-based produced water environmental risk assessment. • We combine a fate-transport model, an uptake-elimination model, and an effect model. • The model incorporates dynamic and site-specific information. • This represents a higher level of detail compared to current practice (e.g. EIF). [ABSTRACT FROM AUTHOR]

This study characterizes and evaluates the constituents of produced water at production wells and dumping sites. The study examined the impact of offshore petroleum mining activities on aquatic systems for regulatory compliance and the selection of management and disposal options. The physicochemical analyses of produced water from the three study locations were within the permissible range for pH, temperature, and conductivity. Of the four heavy metals detected, mercury had the lowest concentration at 0.002 mg/L, while arsenic the metalloid, and iron had the highest concentrations at 0.038 mg/L and 36.1 mg/L, respectively. The total alkalinity values for the produced water in this study are about six-fold compared to the other three locations (Cape Three Point, Dixcove, University of Cape Coast). Compared to the other locations, produced water had higher toxicity to Daphnia, with an EC 50 value of 80.3 %. The levels of polycyclic aromatic hydrocarbons (PAHs), volatile hydrocarbons, and polychlorinated biphenyls (PCBs) analyzed in this study were all insignificant in terms of toxicity. The total hydrocarbon concentrations indicated a high level of environmental impact. However, considering the possible breakdown of total hydrocarbons over time, and the marine ecosystem's high pH and salinity conditions, further recordings and observations should be conducted to ascertain the overall cumulative effects of oil drilling activities at the Jubilee oil fields along the shores of Ghana. • Produced water is potentially harmful to the marine environment. • The total hydrocarbon concentrations indicated a high level of environmental impact. • Hg, Fe, Zn, Cu, and As were identified in produced water. • Total alkalinity for produced water was eight times higher than in other locations. • Produced water was observed to have higher toxicity on Daphnia magna. [ABSTRACT FROM AUTHOR]

The characterization of inorganic elements in the produced water (PW) samples is a difficult task because of the complexity of the matrix. This work deals with a study of a methodology for dissolved Fe quantification in PW from oil industry by flame atomic absorption spectrometry (FAAS) after cloud point extraction (CPE). The procedure is based on the CPE using PAN as complexing agent and Triton X-114 as surfactant. The best conditions for Fe extraction parameters were studied using a Box-Behnken design. The proposed method presented a LOQ of 0.010 μg mL − 1 and LOD of 0.003 μg mL − 1 . The precision of the method was evaluated in terms of repeatability, obtaining a coefficient of variation of 2.54%. The accuracy of the method was assessed by recovery experiments of Fe spiked that presented recovery of 103.28%. The method was applied with satisfactory performance to determine Fe by FAAS in PW samples. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO 2 ) mineralogical sequestration using oil-field brines (above-ground field brines) is gaining attention for the storage of CO 2 into stable mineral carbonates. This involves complex processes that are affected by brine composition, pressure, temperature and pH where the latter is the key parameter, as carbonation conversion rates and the specific carbonates species formed are strongly dependent on pH. This study investigates the effect of iron (Fe) in the pH of three synthetic brines prepared as analogue to oil-field brine by combining a number of experimental and modelling tools to elucidate whether or not Fe speciation may affect the pH of brines. X-Ray powder Diffraction (XRD) analyses were also carried out to characterise the mineralogy of the synthetic brines. Results indicate that the Fe speciation affects the pH of oil-field brines; brines containing Fe 3+ experiment a rapid increase of the pH as a consequence of Fe 2 O 3 precipitation by aging of Fe(OH) 3 under alkaline conditions. Brines containing Fe 2+ show a sharp drop of the pH as a result of air oxidation of highly alkaline Fe(OH) 2 suspension induced by KOH addition by means of dissolution-oxidation-crystallisation mechanism where particles of Fe(OH) 2 provide the substrate for the γ-FeO(OH) growth. The master variable governing the rates at which these compounds form is pH. [ABSTRACT FROM AUTHOR]

We tested nine hydrophobically modified polyacrylamides with molecular weights situated between 1.58 and 0.89 × 10 6 g/mol for enhanced oil recovery applications. Their solution properties were investigated in the distilled water, brine solution, formation water and sea water. Their critical association concentrations were determined from the relationship between their concentrations and the corresponding apparent viscosities ( η app ) at 30 °C at shear rate 6 s −1 . They were between 0.4 and 0.5 g/dl. The brine solutions of 0.5 g/dl of HM-PAMs were investigated at different conditions regarding their apparent viscosities. Such conditions were mono and divalent cations, temperature ranging from 30 to 90 °C, the shear rate ranging from 6 to 30 s −1 and the aging time for 45 days. The surface and interfacial tensions for the HM-PAMs were measured for concentration range from 0.01 to 1 g/dl brine solutions at 30 °C and their emulsification efficiencies were investigated for 7 days. The discrepancy in the properties and efficiencies of the tested copolymers was discussed in the light of their chemical structure. [ABSTRACT FROM AUTHOR]

Produced water management at oil and gas fields is gaining vast attention due to its large volume, high salinity and high disposal cost. Opportunities for disposal by such methods as remote injection are shrinking and increasingly costly. On the other hand, gas flaring at the oil and gas fields wastes large amounts of thermal energy that could potentially be used to reduce the produced water disposal cost. In this paper, a coupled thermal vapor compression (TVC) desalination process powered by flare gas is proposed and rigorously simulated in Aspen Plus. Based on that, the energy intensity and unit product cost ($/vol. of product) are estimated and compared with multistage flash (MSF), multi-effect distillation (MED), mechanical vapor compression (MVC) and reverse osmosis (RO). Sensitivity analysis is also performed to obtain the ranges of energy intensity and production cost, which are influenced by the water salinity, boiling brine temperature, compression ratio, and motive steam pressure. Results indicate that the proposed TVC process is technically viable and cost-effective at most locations; it could also save roughly one-third of the disposal cost compared to the remote injection method. [ABSTRACT FROM AUTHOR]

If large-scale CO 2 sequestration operations are implemented in oilfields or coal mines, large volumes of water (i.e., produced water) could potentially be generated that would need to be properly managed. In this work, produced water samples with total dissolved solids (TDS) values of 18,000–102,000 mg/L (ppm) were collected from an oilfield, a coal-bed methane field, and a coal mine in the Illinois Basin of the United States and were treated by selected conventional pretreatment processes followed by a reverse osmosis desalination process. Pretreatment processes included coagulation by lime, ferric chloride, or aluminum sulfate; filtration by sand, walnut shells, anthracite coal, or microfiltration; and adsorption by organoclay, activated carbon, or ion-exchange resins. Selected pretreatment processes were sufficient for removing most of the contaminants, but the high sodium background of the high-TDS produced water (102,000 ppm) limited the effectiveness of the ion-exchange pretreatment in removing scale-forming species. Reverse osmosis was a practical process for desalination of pretreated produced water samples tested (by reducing the TDS more than 96%) except for the high-TDS produced water. Reported bench-scale produced water treatment data might be beneficial for the design and operation of pilot-scale plants for treating produced waters with similar properties. [ABSTRACT FROM AUTHOR]

One of key challenges for reusing oilfield-produced water as boiler feedwater was desilication, which can produce large amounts of silica sludge and concentrated solutions causing serious secondary pollution. In this paper, an environmentally friendly method that oilfield-produced water is treated by advanced softening without desilication (AS) was conducted via a lab-scale test. Experimental results showed that average scaling rate of the AS was only 0.0018 g/l, which was only a third of that of traditional desilication (0.0056 g/l). Si content in scales formed by AS was less than that of traditional desilication, indicating that softening is more effective than desilication in controlling silicate scales. These suggested that more free silicates and silica can be taken away as volatile by saturated steam under the conditions of 285 °C and 7 MPa. However, these findings can offer an important reference for reusing the oilfield-produced water without desilication into boiler. [ABSTRACT FROM AUTHOR]

Stringent and periodic iteration of regulations related to the monitoring of chemical releases from the offshore oil and gas industry requires the use of ever changing, rapidly developing and technologically advancing techniques. Passive samplers play an important role in water column monitoring of produced water (PW) discharge to seawater under Norwegian regulation, where they are used to; i) measure aqueous concentrations of pollutants, ii) quantify the exposure of caged organisms and investigate PW dispersal, and iii) validate dispersal models. This article summarises current Norwegian water column monitoring practice and identifies research and methodological gaps for the use of passive samplers in monitoring. The main gaps are; i) the range of passive samplers used should be extended, ii) differences observed in absolute concentrations accumulated by passive samplers and organisms should be understood, and iii) the link between PW discharge concentrations and observed acute and sub-lethal ecotoxicological end points in organisms should be investigated. [ABSTRACT FROM AUTHOR]

The Weyburn oil field in Saskatchewan, Canada, is hosted in Mississippian carbonates and has been subject to injection of CO 2 since 2000. A detailed mineralogy study was completed as the basis for modeling of mineral storage of injected CO 2 . Combining the mineralogy with kinetic reaction path models and water chemistry allows estimates of mineral storage of CO 2 over 50 years of injection. These results, combined with estimates of pore volume, solubility of CO 2 in oil and saline formation waters, and the initial and final pore volume saturation with respect to oil, saline water and gas/supercritical fluid allow an estimate of CO 2 stored in saline water, oil and minerals over 50 years of CO 2 injection. Most injected CO 2 is stored in oil (6.5 × 10 6 –1.3 × 10 7 t), followed closely by storage in supercritical CO 2 (7.2 × 10 6 t) with saline formation water (1.5–2 × 10 6 t) and mineral storage (2–6 × 10 5 t) being the smallest sinks. If the mineral dawsonite forms, as modeling suggests, the majority of CO 2 dissolved in oil and saline formation water will be redistributed into minerals over a period of approximately 5000 years. The composition of produced fluids from a baseline sampling program, when compared to produced fluids taken three years after injection commenced, suggest that dawsonite is increasingly stable as pH decreases due to CO 2 injection. The results suggest that hydrocarbon reservoirs that contain low gravity oil and little or no initial gas saturation prior to CO 2 injection, may store the majority of injected CO 2 solubilized in oil, making such reservoirs the preferred targets for combined enhanced oil recovery-CO 2 storage projects. [ABSTRACT FROM AUTHOR]

• A new type of MOF-based solar steam generator with a layered architecture, in which a hydrophilic MOF membrane serves the water sorbent and Ti 2 O 3 @PEDOT-OH as a solar absorber. • This new architecture creates a transmembrane temperature gradient, which maximizes water adsorption and desorption during desalination. • The device achieves the highest average evaporation rate of 2.20 kg.m−2.h−1 and produces water with ion concentrations lower than the drinkable water standard suggested by WHO by three orders of magnitudes. To develop an efficient solar steam generation platform based on the hydrophilic metal-organic framework for producing potable water from seawater or wastewater. Solar steam generation and desalination membranes have attracted much attention due to their intrinsic advantages of energy consumption entirely from solar irradiation and no pollutants produced. Ti 2 O 3 nanoparticles blended with poly(hydroxymethyl EDOT) (Ti 2 O 3 @PEDOT-OH) as photothermal conversion nanocomposites are coated on synthesized CAU-10-H membranes This architecture creates a transmembrane temperature gradient, which optimizes water adsorption and desorption efficiency. The device with CAU-10-H in 13 μm of thickness achieves the highest average evaporation rate of 2.20 kg.m−2.h−1 and evaporation efficiency of 98%. Also, the ion concentrations of the produced water are lower than the drinkable water standard. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study we investigated the removal of silica and hardness by continuous electrocoagulation (EC), based on treatment of oil-sands produced water. The effect of operating parameters including charge loading, flow rate, current density and polarity reversal period were investigated. As expected, the removal of silica and hardness increased with charge loading. At a fixed charged loading, the flowrate was found to have only a slight impact on silica removal. With both Fe and Al electrodes, a slight decrease in contaminant removal was observed at high flow rates, likely due to the shear breakup of flocs. For the range of conditions studied, the removal of Si, Ca and Mg increased with the polarity reversal time (from 30 s to 10 min), while the cell voltage (and energy consumption) decreased. The cell voltage obtained with 10 min polarity reversal was significantly lower than that for DC-EC. More than 80 % silica removal was achieved using a current density of 8 mA cm–2, charge loadings of 1500 C L⁻1 and 1000 C L⁻1 with Fe and Al electrodes respectively. Al-EC was found to consume less electrode material and energy while achieving higher Si, Ca, and Mg removal compared to Fe-EC. Economic evaluation revealed that for >80 % Si removal the specific energy consumption was 1.13 and 0.70 kWh m–3, with a total operating cost C$0.54 and C$0.50 per m3 of water treatment, for Fe and Al-EC respectively. [Display omitted] • Silica removal by EC is higher with Al electrodes compared to Fe. • Flowrate was found to have a slight impact on silica removal with both Fe and Al. • Current density was found to have no significant effect on silica removal. • Polarity reversal with an interval of 10 min was found to reduce cell voltage. • Rate of electrode consumption and energy use was less for Al-EC than Fe-EC. [ABSTRACT FROM AUTHOR]

During hydraulic fracturing, wastewaters - termed flowback and produced water (FPW) - are created as a by-product during hydrocarbon extraction. Given the large volumes of FPW that a single well can produce, and the history of FPW release to surface water bodies, it is imperative to understand the hazards that hydraulic fracturing and FPW pose to aquatic biota. Using rainbow trout embryos as model organisms, we investigated impacts to cardio-respiratory system development and function following acute (48 h) and sub-chronic (28-day) FPW exposure by examining occurrences of developmental deformities, rates of embryonic respiration (MO 2), and changes in expression of critical cardiac-specific genes. FPW-exposed embryos had significantly increased rates of pericardial edema, yolk-sac edema, and tail/trunk curvatures at hatch. Furthermore, when exposed at three days post-fertilization (dpf), acute 5% FPW exposures significantly increased embryonic MO 2 through development until 15 dpf, where a switch to significantly reduced MO 2 rates was subsequently recorded. A similar trend was observed during sub-chronic 1% FPW exposures. Interestingly, at certain specific developmental timepoints, previous salinity exposure seemed to affect embryonic MO 2 ; a result not previously observed. Following acute FPW exposures, embryonic genes for cardiac development and function were significantly altered, although at termination of sub-chronic exposures, significant changes to these same genes were not found. Together, our evidence of induced developmental deformities, modified embryonic MO 2 , and altered cardiac transcript expression suggest that cardio-respiratory tissues are toxicologically targeted following FPW exposure in developing rainbow trout. These results may be helpful to regulatory bodies when developing hazard identification and risk management protocols concerning hydraulic fracturing activities. [Display omitted] • Impacts of flowback and produced water (FPW) exposure on salmonid development and cardio-respiratory function. • Increased mortality, pericardial and yolk-sac edema, and tail/spine curvatures in exposed embryos. • Exposed embryos displayed altered respiration past initial acute exposures. • Altered expression of key cardiac developmental, structural, and electrophysiological genes. • Embryos earlier in development were more susceptible to FPW-induced sublethal toxicity. [ABSTRACT FROM AUTHOR]

The rapid growth of demand for lithium, especially in lithium batteries calls for an increase in the supply of lithium resources. We synthesized H 1.33 Mn 1.67 O 4 adsorbent by solid-phase reaction method to recover lithium for the first time from shale gas flowback and produced water (SGFPW) in the Sichuan Basin, China. Na 2 CO 3 precipitation pre-treatment was employed to improve the adsorption capacity and selectivity of lithium. The adsorption capacity of lithium in the pre-treated water (P-SGFPW) was 16.24 mg/g higher than that in SGFPW (13.27 mg/g), and the partition coefficient of Li+ increased from 731.58 to 1073.58 mL/g after precipitation. After four cycles of adsorption and desorption, the adsorption capacity of lithium was stable and showed only a slight decrease equal to 3.53% and 5.35% in P-SGFPW and SGFPW, respectively. H 1.33 Mn 1.67 O 4 is a promising adsorbent for lithium extraction from SGFPW, and precipitation before adsorption can improve its performance significantly. [Display omitted] [ABSTRACT FROM AUTHOR]

The crude oil drilling and extraction operations are aimed to maximize the production may be counterbalanced by the huge production of contaminated produced water (PW). PW is conventionally treated through different physical, chemical, and biological technologies. The efficiency of suggested hybrid electrobiochemical (EBC) methods for the simultaneous removal of total petroleum hydrocarbon (TPH) and sulfate from PW generated by petroleum industry is studied. Also, the factors that affect the stability of PW quality are investigated. The results indicated that the effect of biological treatment is very important to keep control of the electrochemical by-products and more TPH removal in the EBC system. The maximum TPH and sulfate removal efficiency was achieved 75% and 25.3%, respectively when the detention time was about 5.1 min and the energy consumption was 32.6 mA/cm 2 . However, a slight increasing in total bacterial count was observed when the EBC compact unit worked at a flow rate of average 20 L/h. Pseudo steady state was achieved after 30 min of current application in the solution. Also, the results of the study indicate that when the current intensity was increased above optimum level, no significant results occurred due to the release of gases. [ABSTRACT FROM AUTHOR]

In order to increase the applicability of photocatalysis in treating offshore produced water (OPW), an immobilized catalyst was introduced into the UV irradiation system and its performance on the degradation of organic compounds in OPW was evaluated. Naphthalene was selected as the target pollutant owing to its abundance in produced water and its chemical property as a typical polycyclic aromatic hydrocarbon. Aeroxide® P25 nano-scale TiO2 powder was immobilized on glass slides by a heat attachment method and its photocatalytic capacity was compared to that of the original powder in terms of naphthalene removal efficiency. The results of adsorption showed that the reduction of catalysts' surface area by immobilization was similar to that by agglomeration. The photocatalytic reaction rate constants in the homogeneous and immobilized systems were 0.00219 min-1 and 0.00305 min-1, respectively, indicating that the immobilized catalyst had a better performance in photo-oxidation. The fouling of catalyst surface during the irradiation process came from the deposition of insoluble particles, organic matter, and the scaling of calcium. The immobilization of catalysts was more resistant to the substrate effects of OPW, indicating a promising alternative in treating OPW. [ABSTRACT FROM AUTHOR]